1. The Field of the Invention
The present invention is in the field of dental retention devices. In particular, the present invention relates to dental wedges that are used for separating teeth and for holding matrix bands against teeth during dental procedures. Even more particularly, the present invention relates to dental wedges comprising mechanically flexible features.
2. The Prior State of the Art
In the field of dentistry, dental practitioners often treat patients who have developed cavities in teeth. In order to treat cavities the dental practitioner removes the infected portion of the tooth and then deposits a filling material such as a composite, a resinous material, or an amalgam into the tooth preparation.
During the dental filling procedure, a matrix band is typically placed against the side of the tooth to keep the filling material within the tooth preparation from flowing beyond the desired boundary of the restored tooth. A matrix band typically comprises a thin metallic or plastic strip that is flexible and can be bent around the tooth being restored. If the matrix band is not properly held in place then the filling may be expressed beyond the tooth preparation, thereby distorting the configuration of the restored tooth and possibly causing ledges or overhangs, which can be problematic to adjacent tissues and inhibit cleaning.
An improper filling can lead to dental discomfort, misalignment of teeth, capture of food particles, infections, and other dental problems. To avoid these problems, and to fix a distorted dental filling, it may be necessary to grind or drill the filling material down to the proper shape, or even replace the filling entirely. It is desirable to avoid this process because it can increase the time and expense of restoring the tooth and can also create anxiety and discomfort to the patient being treated. Accordingly, it is desirable to keep the matrix band in proper placement during the filling procedure so that the dental filling material molds into a shape that approximates the desired shape of the restored tooth and fits precisely.
In order to hold the matrix band in a desired placement, small dental wedges are often placed into the interproximal spaces between the matrix band and the adjacent tooth. Sometimes, dental wedges are also used to separate the teeth to make room to accommodate, or to compensate for, the thickness of the matrix band between the teeth. Existing dental wedges are typically composed of a wood or semi-rigid plastic material having properties that enable the dental wedge to be slightly deformed while maintaining a sufficiently rigid or semi-rigid structure. These properties generally enable the dental wedge to force teeth apart without damaging the teeth. After the dental wedge is removed the compressed periodontal fibers return to their original dimension and cause the displaced teeth to return to their designated positions.
One inherent problem with the use of dental wedges, however, is that they are prone to slipping out from between the teeth during the dental procedure because the frictional forces holding the dental wedges in place are not adequate. Additionally, existing dental wedges are particularly susceptible to slipping out of place because they are generally incapable of conforming to and accommodating the irregularities of, and between, the teeth. They therefore make only limited contact- with the teeth, thereby further limiting the frictional forces necessary to hold the dental wedges in place. This is particularly problematic when the surfaces of the dental wedges become wet and slippery from the patient""s saliva or blood, thereby further decreasing the friction that is applied over this limited area of contact between the dental wedges and the surfaces of the teeth.
One attempt to address the problems associates with rigid wedges is the FLEXI-WEDGE, which is made from a semi-rigid plastic material and which has a generally upside-down V-shaped cross section. This makes it capable of flexing along its base as it is forced between teeth. Nevertheless, the FLEXI-WEDGE also suffers from an inability to accommodate and conform to irregularities of, and between, the teeth.
Accordingly, there is currently a need in the art for an improved dental wedge with improved retention capabilities for remaining in place within the interproximal space between teeth, for spacing teeth apart, and for holding matrix bands in proper placement during dental procedures.
The present invention is directed to improved dental wedges for use in dental procedures. In particular, dental wedges of the invention have protruding flexible members that help the dental wedges stay in place when inserted between adjacent teeth.
In one presently preferred embodiment, a dental wedge of the invention comprises a rigid body that is substantially wedge shaped, tapering from a head to a tip and comprises multiple flexible members that protrude away from the sides of the dental wedge. Said in another way, the sides of the dental wedge are serrated, with multiple tines or teeth protruding away from the sides of the dental wedge. According to one presently preferred embodiment, these protrusions or members that protrude away from the sides of the dental wedge are somewhat flexible and are configured to bend when they are subjected to an adequate force, such as when being inserted between two adjacent teeth.
It should be appreciated that the shape and size of the flexible members may vary to accommodate different needs and preferences. For instance, the flexible members may be rounded, pointed, curved, rectilinear, triangular, straight, thin, thick, textured, smooth, or any combination thereof.
In one preferred embodiment, the body of the dental wedge and the flexible members comprise an integrated unit that is manufactured during a single process, such as by injection molding or casting. According to this embodiment, the body of the dental wedge and the flexible members may be composed of a semi-rigid material, such as nylon, polycarbonate, polystyrene, polyethylene, and polypropylene. It should be appreciated, however, that the dental wedges of the invention may also comprise other suitable materials, including, but not limited to various thermoplastics, thermoset plastics, and chemical set plastics.
According to one alternative embodiment, the flexible members are formed separately from the body and are subsequently attached to the body, such as with ultrasonic welding, friction welding, or insert molding. The flexible members may also be attached to the body with an adhesive, such as with glue, epoxy, or cement. The flexible members may be composed of the same material as the body or of a different material.
In one preferred embodiment, when a dental wedge of the invention is inserted between adjacent teeth, the flexible members are forced to bend between the teeth and the body of the dental wedge, thereby enabling the flexible members to conform to the surfaces of the teeth. By conforming to the shape of the teeth, the flexible members are able to increase the surface area over which friction is applied to the dental wedge, thereby helping hold the dental wedge in place and keeping the dental wedge from slipping out from between the teeth. To further enhance the retention capabilities of the dental wedges of the invention, the flexible members may also be configured with sharp edges or gritty surfaces that can catch onto irregularities of the tooth surface, thereby increasing the frictional forces applied by the dental wedge.
The dental wedges of the invention can also be used to securely hold a matrix band conformingly in place against a tooth. For instance, when a dental wedge of the invention is placed next to a matrix band between adjacent teeth, the flexible members of the dental wedge apply multiple discrete forces to the matrix band urging the matrix band to conform to the shape of the tooth.
These, as well as other, benefits, features and advantages of the dental wedges of the present invention will become more fully apparent from the following description and appended claims, or may be learned by practicing the invention as set forth below.